Heavy Oil Extraction Research Articles

The influence of compound heating power distribution on heat transfer

With the continuous deepening of oil and gas resource development, the number of large cargo tankers is increasing rapidly, and the tankers need to heat and keep the cargo oil in the tanks during navigation. However, the traditional steam coil heating method has many problems, such as low thermal efficiency and large total fuel consumption, which will cause energy waste and increasing oil tanker transportation costs. Microwave heating technology has the characteristics of fast, uniform and efficient heating, and is widely used in petroleum extraction and viscosity reduction of heavy oil. This paper proposes a new heating method of steam-microwave composite heating to heat the cargo in the tanker cabin. Taking a VLCC side cabin as a prototype, a three-dimensional numerical scale model is established through COMSOL software to study the influence of thermal efficiency under different power distribution between steam and microwave. The research results show that when the total power is constant, the smaller the proportion of microwave power, the more beneficial it is to improve the heat transfer efficiency in oil heating. This research has important guiding significance for improving oil heating efficiency and saving energy consumption.

Multi-molecular mixed polymer flooding for heavy oil recovery

Polymer flooding has its superiority in heavy oil recovery due to the improvement of the mobility ratio of oil to the injected fluids. In this work, the multi-molecular mixed polymer flooding is proposed for heavy oil recovery. Firstly, the inaccessible pore volume and resistance coefficient are measured for the multi-molecular mixed polymer. The low-field nuclear magnetic (LFNMR) resonance technique is then applied to compare the performance of conventional polymer flooding and multi-molecular mixed polymer flooding for heavy oil extraction from the pore-scale perspective. Results show that the inaccessible pore of multi-molecular mixed polymer flooding is about 5.0% lower than the single molecular polymer flooding, of which the resistance coefficient is about 6.2 higher than the single molecular polymer flooding, indicating the potential of the multi-molecular mixed polymer flooding for enhancing heavy oil recovery. Moreover, the multi-molecular mixed polymer flooding shows excellent performance for heavy oil production compared to the conventional polymer flooding. Specifically, the total oil recovery for the multi-molecular mixed polymer flooding is measured about 4.2% higher than that of the conventional polymer flooding. In addition, based on the LFNMR scanning, the multi-molecular mixed polymer flooding is more efficient in extracting oil from the smaller pores. This study is expected to inspire new strategies for heavy oil recovery; more importantly, it may provide insights into the mechanism of polymer flooding for heavy oil extraction.

Modeling of Heavy-Oil Flow with Regard to Their Rheological Properties

With the depletion of traditional energy resources, the share of heavy-oil production has been increasing recently. According to some estimates, their reserves account for 80% of the world’s oil resources. Costs for extraction of heavy oil and natural bitumen are 3–4 times higher than the costs of extracting light oil, which is due not only to higher density and viscosity indicators but also to insufficient development of equipment and technologies for the extraction, transportation, and processing of such oils. Currently, a single pipeline system is used to pump both light and heavy oil. Therefore, it is necessary to take into account the features of the heavy-oil pumping mode. This paper presents mathematical models of heavy-oil flow in oil-field pipelines. The rheological properties of several heavy-oil samples were determined by experiments. The dependencies obtained were used as input data for a simulation model using computational fluid dynamics (CFD) methods. The modeling condition investigates the range of shear rates up to 300 s−1. At the same time, results up to 30 s−1 are considered in the developed computational models. The methodology of the research is, thus, based on a CFD approach with experimental confirmation of the results obtained. The proposed rheological flow model for heavy oil reflects the dynamics of the internal structural transformation during petroleum transportation. The validity of the model is confirmed by a comparison between the theoretical and the obtained experimental results. The results of the conducted research can be considered during the selection of heavy-oil treatment techniques for its efficient transportation.

Removal of oil from sandstone rocks by solid-liquid extraction using oil phase-free microemulsion systems

The impregnation of oil on solid surfaces is a major challenge currently due to the need to purify environments affected by disasters and accidents related to the oil and gas industry. In this work, microemulsion systems without oil phase were formulated containing nonionic surfactants of different degrees of ethoxylation (10, 8 and 6 ethoxylation bonds) for the solid-liquid extraction of heavy oil impregnated in sandstone rocks. A central composite design was carried out showing the total oil extraction efficiency (%EE) entre 3.680 ± 0.933 e 99.800 ± 0.266. Micellar comparison analyses showed the importance of alcohol in the process, since 20% more oil was removed in the presence of alcohol, and the use of oil-free microemulsions proved to be feasible in cross-current and counter-current processes, especially the system containing lauryl alcohol with six ethoxylation bonds (LA 6EO) that reached satisfactory oil extraction results on both processes (%EE ≥ 90%).

Улучшение условий труда шахтеров-нефтяников при переходе от термошахтного способа добычи высоковязкой нефти на модульно-шахтный способ разработки Ярегского месторождения

The need for high-viscosity oil production in the fields of the Russian Federation is substantiated. The technology of high-viscosity oil production by the thermoshaft method is considered, harmful and hazardous factors at the workplaces of the underground group workers are identified, first of all, the microclimate parameters (increased air temperature of the working area), which effect on the formation of occupational diseases and an increase in the risk of injury to the personnel. The main problems associated with the imperfection of the technology of the thermoshaft method for the extraction of high-viscosity oil, which effect on the safety of conducting operations for the extraction of heavy oil, are investigated, and presented. The options of opening up a high-viscosity oil field with a modular mine, which allows to normalize the thermal regime in mine workings, improve working conditions of the oil miners, reduce the level of occupational diseases and injury rate, reduce the volume of work and the costs of mining operations and maintenance of the mine workings, are considered. The system for the development of the Yaregskoye field of high-viscosity oil with the division of the mine field into separate production blocks using a sectional ventilation scheme, which provides for independent ventilation of each module due to the construction of an air supply and air exhaust shafts in each block-module of the mine is proposed in the article. The surface and underground complex of shafts for the construction of a modular mine is presented. The calculation is carried out and the results of technical solutions for airing various modifications of mini — mines are given. The drilling gallery was designed, which is typical for all the options of opening. In the designed modular mines, a closed oil gathering system is proposed. Comparative economic analysis showed the efficiency of the development of new areas of the Yaregskoye high-viscosity oil field using the construction of modular mines.

Synthesis of sodium nanoparticles for promising extraction of heavy oil

As reserves of conventional light oil become depleted, recovery of viscous oil is urgently needed to meet increasing energy demands worldwide before clean energy sources are fully developed. Current oil extraction technologies suffer from low efficiency, high cost, and environmental concerns. Attempts to use nanotechnology in this field have thus far been recognized to have only auxiliary effects, rather than playing a major role. Here we report a reactive sodium nanoparticle fluid able to in situ recover highly viscous crude oil very effectively even at room temperature. Its high recovery performance is based on a chemical reaction that allows the nanofluid to exhibit multiple benefits in displacing subsurface oil: heat, hydrogen gas, and sodium hydroxide. In addition, multi-stage nanofluid injection is found to be superior to a single injection mode. Thus, it opens a new way to extract and process crude oil.

Extraction Rate in Vapor Assisted Extraction of Heavy Oil (VAPEX)

Heavy oil recovery requires either heat (SAGD) or a solvent (VAPEX) to reduce its high viscosity first and then the less viscous oil can be recovered. We show here that the existing data on oil recovered in VAPEX process in sandpacks show a square root dependence on the height of pay zone, following expectation. This dependence had remained uncertain and is of importance in oil field operation.

Study of associated gas components and combustion characteristics based on nitrogen-assisted steam stimulation of heavy oils

Nitrogen-assisted steam stimulation (NASS) technology is a widely used heavy oil extraction technology. Most previous studies on the NASS of heavy oil focused on recovery improvements. To study the safety of the associated gas generated during the NASS process of heavy oil, a series of simulation experiments was performed on oil samples from a heavy oil reservoir. The results showed that the effect of pressure and temperature on the components of the associated gas can be ignored during the nitrogen injection. In the process of steam injection, the higher the oxygen content in the injected gas is, the greater the amount of produced combustible gas becomes, which is dangerous. Experiments on the associated gas flammability were conducted to study the effects of temperature (40–120 °C) and pressure (1–15 MPa) on the upper flammability limit (UFL), lower flammability limit (LFL) and limiting oxygen concentration (LOC). The results showed that an increase in the initial pressure or temperature led to a wider flammability limit range, and the LOC decreased. During the tests, the explosive limit of the flammable mixture ranged from 1.02% to 60.05%, and the lowest LOC was 8.2%. These results are meaningful for safety control in heavy oil development.

Comprehensive study on cleaner production of heavy oil from Athabasca oil sands using chemical additives in biodiesel-assisted ambient-aqueous bitumen extraction process

The massive unconventional petroleum resources of Athabasca oil sands in Alberta, Canada are currently being excavated and processed using the hot water bitumen extraction (HWBE) process and steam-assisted gravity drainage (SAGD) technology. A major challenge associated with HWBE process is high energy intensity for maintaining an operation temperature of 40–55 °C. Solvent-assisted ambient aqueous bitumen extraction processes, in which a portion of solvent is added for oil sands pretreatment prior to extraction process, have been reported to be capable of reducing the energy intensity via ambient temperature oil sands extraction operations. However, there is still a gap between the current solvent-assisted process and industrial expectations. This study focuses on optimization of biodiesel-assisted ambient aqueous bitumen extraction, an example of the solvent-assisted process, by incorporating methyl isobutyl carbinol (MIBC) and ethylene oxide-propylene oxide (EO-PO) copolymer in oil sands pretreatment. The idea is to take advantage of such chemicals and demulsifiers used downstream of heavy oil (known as bitumen) extraction process by their addition upfront as in the case of biodiesel-assisted hybrid extraction process. With the incorporation of these chemicals and demulsifiers in the improved biodiesel-assisted process, both bitumen liberation and bitumen flotation efficiency were improved significantly with the addition of biodiesel/MIBC mixture at 10 wt% of bitumen. The results from bench-scale experiments revealed a higher bitumen recovery and a cleaner bitumen froth by the improved biodiesel-assisted process at ambient temperature as compared with the traditional biodiesel-assisted process, as well as current industrial HWBE process, featuring a cleaner production of heavy oil from Athabasca oil sands and other heavy oil resources.

Investigating the Influence of Heavy Oil Recovery by In Situ Combustion during Air Injection as EOR Technique

Heavy oil is one of the most useful energy resources specially in the times of crises when other resources are not present in profusion. However, Occurrence of heavy oil in unconsolidated sands is one the most challenging factor to recover the heavy oil. Therefore, in this study the main focus is derived towards the extraction of heavy oil with optimistic procedure called air injection. For the research, a reactor assembly was developed for the experimental work on air (21% oxygen) injection into heavy oil (12.59 °API) reservoir. Total 13 kinetics runs were conducted on unconsolidated cores by varying the parameters involved system pressure, flow rate (air flux), oxidation temperature (heat input), and rock formation (sand matrix). It was found that the process is very dependent on operating conditions employed, as oxygen consumption rate was very dependent on air flux. Increase of air flux from 15.19 to 22.78 m3/m2-hr resulted in slightly increasing rates of oxygen consumption over the temperature range under investigation. The temperature difference also shows great effect on the high temperature oxidation. The pressure and porous media also have great impact on the combustion behavior. The influence of individual parameter was obtained from analysis of the inlet oxygen and composition of flue gases from the combustion cell. Indeed, the oxygen conversion was too less to evaluate the kinetic data at temperature less than 250 °C while for oxidation reactions, the oxygen statistics analyzed from temperature above than 350 °C. The experimental results reveal that the average maximum peak temperature was 440 °C, and the oxidation reaction process at high temperature was very effective in terms of produced carbon oxides with an average percentage of 9.5% CO2, 5.5% CO in flue gases. Oil displacement was observed from the analysis of flue gases, consequently; incremental oil recovery was achieved between 56%-80% under high temperature oxidation (HTO) conditions.

Investigating the Influence of Heavy Oil Recovery by In Situ Combustion during Air Injection as EOR Technique

Heavy oil is one of the most useful energy resource special in the times of crises when other resources are not present in profusion. However, Occurrence of heavy oil in unconsolidated sands is one the most challenging factor to recover the heavy oil. Therefore, in this study the main focus is derived towards the extraction of heavy oil with optimistic procedure called air injection. For the research, a reactor assembly was developed for the experimental work on air (21% oxygen) injection into heavy oil (12.59 °API) reservoir. Total 13 kinetics runs were conducted on unconsolidated cores by varying the parameters involved system pressure, flow rate (air flux), oxidation temperature (heat input), and rock formation (sand matrix). It was found that the process is very dependent on operating conditions employed, as oxygen consumption rate was very dependent on air flux. Increase of air flux from 15.19 to 22.78 m 3 /m 2 -hr resulted in slightly increasing rates of oxygen consumption over the temperature range under investigation. The temperature difference also shows great effect on the high temperature oxidation. The pressure and porous media also has great impact on the combustion behavior. The influence of individual parameter was obtained from analysis of the inlet oxygen and composition of flue gases from the combustion cell. Indeed, the oxygen conversion was too less to evaluate the kinetic data at temperature less than 250 °C while for oxidation reactions, the oxygen statistics analyzed from temperature above than 350 °C. The experimental results reveal that the average maximum peak temperature was 440 °C, and the oxidation reaction process at high temperature was very effective in terms of produced carbon oxides with an average percentage of 9.5% CO 2 , 5.5% CO in flue gases. Oil displacement was observed from the analysis of flue gases, consequently; incremental oil recovery was achieved between 56%-80% under high temperature oxidation (HTO) conditions.

Investigating the Influence of Heavy Oil Recovery by In Situ Combustion during Air Injection as EOR Technique

Heavy oil is one of the most useful energy resource special in the times of crises when other resources are not present in profusion. However, Occurrence of heavy oil in unconsolidated sands is one the most challenging factor to recover the heavy oil. Therefore, in this study the main focus is derived towards the extraction of heavy oil with optimistic procedure called air injection. For the research, a reactor assembly was developed for the experimental work on air (21% oxygen) injection into heavy oil (12.59 °API) reservoir. Total 13 kinetics runs were conducted on unconsolidated cores by varying the parameters involved system pressure, flow rate (air flux), oxidation temperature (heat input), and rock formation (sand matrix). It was found that the process is very dependent on operating conditions employed, as oxygen consumption rate was very dependent on air flux. Increase of air flux from 15.19 to 22.78 m 3 /m 2 -hr resulted in slightly increasing rates of oxygen consumption over the temperature range under investigation. The temperature difference also shows great effect on the high temperature oxidation. The pressure and porous media also has great impact on the combustion behavior. The influence of individual parameter was obtained from analysis of the inlet oxygen and composition of flue gases from the combustion cell. Indeed, the oxygen conversion was too less to evaluate the kinetic data at temperature less than 250 °C while for oxidation reactions, the oxygen statistics analyzed from temperature above than 350 °C. The experimental results reveal that the average maximum peak temperature was 440 °C, and the oxidation reaction process at high temperature was very effective in terms of produced carbon oxides with an average percentage of 9.5% CO 2 , 5.5% CO in flue gases. Oil displacement was observed from the analysis of flue gases, consequently; incremental oil recovery was achieved between 56%-80% under high temperature oxidation (HTO) conditions.

Laboratory investigation of cyclic gas injection using CO2/N2 mixture to enhance heavy oil recovery in a pressure-depleted reservoir

CO2 has strong abilities of oil swelling and viscosity reduction for heavy oil extraction, N2 is a preferable gas media for pressure maintenance, and their mixture is then considered as an alternative method for enhanced oil recovery (EOR) in a pressure-depleted heavy oil reservoir. PVT analysis and cyclic gas injection experiments are conducted to reveal EOR mechanisms for CO2/N2 mixture, and five different CO2/N2 molar ratios (1:0 (pure CO2), 4:1, 7:3, 1:1, and 0:1 (pure N2)) are designed in this paper. PVT analysis shows that the changes of oil properties including saturation pressure, volume factor, and viscosity are highly related to CO2/N2 ratio of the mixture, and a higher CO2/N2 ratio can always lead to better gas/oil interactions. When CO2/N2 ratio is higher than 7:3, the viscosity can reduce to less than 60% of the initial oil viscosity. Gas injection experimental results show that 4:1 mixture can achieve an oil recovery of 17.31%, which is close to the recovery obtained by pure CO2. For the pressure-depleted oil reservoir, simultaneous CO2/N2 injection or N2 followed by CO2 injection is suitable injection mode for the mixture. With such a design of CO2/N2 mixture, an optimized EOR effect can be achieved with gas/oil interactions dominated by CO2 coupled with energy supplement provided by N2. A pilot test of CO2/N2 mixture injection is successfully conducted in a test well, and an oil increment of 337 t is obtained after 40,000 m3 of N2 injection followed by 80,000 m3 of CO2 injection.

The Role of Emulsions in Steam-Assisted-Gravity-Drainage (SAGD) Oil-Production Process: A Review

SummaryStudies that investigate and attempt to model the process of steam-assisted gravity drainage (SAGD) for heavy-oil extraction often adopt the single-phase-flow assumption or relative permeability of the moving phases as a continuous phase in their analyses. Looking at the emulsification process and the likelihood of its prevalence in SAGD, however, indicates that it forms an important part of the entire physics of the process. To explore the validity of this assumption, a review of prior publications that are related to the SAGD process and the modeling approaches used, as well as works that studied the emulsification process at reservoir conditions, is presented. Reservoir conditions are assessed to identify whether the effect of the emulsion is strong enough to encourage using a multiphase instead of a single-phase assumption for the modeling of the process. The effect of operating conditions on the stability of emulsions in the formation is discussed. The review also covers the nature and extent of effects from emulsions on the flow mechanics through pore spaces and other flow passages that result from the well completion and downhole tubing, such as sand/flow-control devices. The primary outcome of this review strengthens the idea that a multiphase-flow scenario needs to be considered when studying all flow-related phenomena in enhanced-oil-recovery processes and, hence, in SAGD. The presence of emulsions significantly affects the bulk properties of the porous media, such as relative permeability, and properties that are related to the flow, such as viscosity, density, and ultimately pressure drop. It is asserted that the flow of emulsions strongly contributed to the transport of fines that might cause plugging of either the pore space or the screen on the sand-control device. The qualitative description of these influences and their extents found from the review of this large area of research is expected to guide activities during the conception stages of research questions and other investigations.

Solvent-dependent recovery characteristic and asphaltene deposition during solvent extraction of heavy oil

Most traditional recovery methods for heavy oil, such as thermal recovery processes, are energy consuming and greenhouse gas emission is intense. Non-thermal based solvent extraction methods are attractive because they require much less heat, no water and the produced heavy oil has low viscosity even at surface conditions, making it easier to transport. However, heavy oil recovery by solvent occurs mainly at the moving solvent front which is only a few millimetres width. It is thus challenging for it to be modelled in reservoir scale and leaves a large uncertainty regarding the recovery factor prediction. For any reliable scaling up, the fundamental details of the extraction in millimetre range down to the pore scale need to be understood. In this study, we use a 2D micromodel operated at reservoir pressure and temperature conditions, in order to analyse the extraction processes of bitumen by solvent. Two different solvents, pentane and propane, which are both considered as field-relevant candidates, are selected for comparison and toluene is selected as a fully miscible reference case. By imaging both the displacement pattern on a larger scale of 5 cm and, simultaneously, the details of the flow processes at pore scale, it was observed that both pentane and propane precipitate asphaltenes. But in the case of pentane, the precipitated asphaltenes are solid which significantly reduce the permeability thus resulting in plugging. The result from flow simulation confirmed the influence of formation plugging on the flow and diffusion process. In the case of propane, the precipitated asphaltenic phase remains liquid, hence mobile, which leads to capillary trapping. Consequently, the recovery factor for propane is ~15% higher than for pentane and more stable. In general, this study suggests that heavy oil recovery using solvent is a dynamic process where the pore scale phase characteristic of asphaltene has a strong influence both on the transport of fresh solvent and the production of dissolved crude components. These differences between the solvent are key and should be included in field scale estimations.

DFT исследование триплетных и синглетных элементарных актов окисления ациклических и циклических алканов, инициированных первичным взаимодействием с 3O2

The primary oxidation stages of 3O2 model acyclic and cyclic alkanes and their subsequent triplet and singlet elementary events were studied for the first time by the DFT method with the density functional B3LYP and basis set 6-311++g(df,p). According to quantum chemical DFT calculations the C–H radical cleavage of the bonds of acyclic and cyclic alkanes upon interaction with 3O2 is almost completely thermodynamically shifted toward the initial state of the reaction system. This energy of primary oxidizing events explains the extremely low reactivity of saturated alkanes in comparison with asphaltene structural fragments under the conditions of SCF technology for the extraction of heavy oils and asphaltenes by a propane-butane mixture. It has been demonstrated that for all elementary acts of primary alkane oxidation the product of the direct reaction direction is not a free pair of radicals but a triplet hydrogen complex with a pronounced hydrogen bond between the hydroperoxyl radical and the radical form of the corresponding hydrocarbon. A new, previously not taken into account very exothermic (H = -29.25 – -30.77 kcal/mol) reaction direction is described which corresponds to triplet recombination of alkyl radicals and a hydroperoxyl radical in its oxygen-concentrated part. The products of this recombination are triplet forms of alkane hydroperoxides in which there is a fairly loosened triplet O---O bond with a length of 2.20-2.23 Å, which is ~0.72-0.77 Å more than bond length in the singlet state.

Study on application of colloidal particles of metal oxides to increase the oil recovery factor

The extraction of heavy oil, including bitumen, is complicated by the extremely high viscosity of the fluid in the reservoir. The adsorption of heavy oil fractions on the surface of minerals leads to the hydrophobization of the pore space. The magnetic colloidal particles of iron oxides present in the composition of the water remove adsorbed oil from the surface of pores, which manifests itself as an increase in the oil recovery factor and the injectivity of injection wells. Iron particles of submicron size, located on the surface of an electrically charged gas bubble, are concentrated at the water-oil interface. Due to the high adsorption energy on the surface of the iron particle, oil is deposited on the iron oxide particles. The drop-in bottom pressure of injection and production wells contributes to the movement of the gas bubble with oil and iron oxides to the bottom of production wells. The study of the mechanism of exposure to electromagnetic radiation showed that the electromagnetic field selectively heats the particles of iron oxide, causing catalytic cracking of oil, and contributes to an increase in the oil recovery factor and well productivity index.

Investigation into atomization spray blending property in heavy crude oil extraction under laboratory conditions

Abstracts In this study, the atomization blending property for heavy crude oil extraction was systematically investigated both numerically and experimentally. In the experiment conducted, the blending behavior was simulated using hydraulic oil and spray with 1:10 light phase-gas atomize volume flow rate ratio in an equipment sharing the same scale as the on-site production. A Malvern Insitec droplet size analyzer was applied for the droplet size measurement, and a quick closing valve method was applied for the phase fraction measurement. A numerical simulation combined with a population balance model and the RNG k-e model was performed under both the corresponding operating conditions and a high-pressure drop environment to further investigate the blending procedure. The results show that the atomization spray blending performs better than the equivalent pure gas lifting method with more crude oil carried at the exit. Under 0.6 m3/h light phase inlet conditions, spray blending brings 8% more heavy crude than gas lifting, and the improvement rises as inlet flow rate increases. Both a droplet and liquid film are present in the casing space before blending for the spray liquid phase. In addition, the light phase droplet diameter decreases with an increase in the inlet flow rates in the lifting pipe after blending. Moreover, the blending behavior differs under various light phase inlet flow rates, while the mixture viscosity is reduced by 50% for the atomization spray method. Each of these factors was shown to be beneficial for refining the blending used in a heavy crude oil extraction technique.

GEOMETRIC AND ELECTRONIC STRUCTURE OF HEAVY HIGHLY VISCOUS OIL COMPONENTS

Physical-chemical and structural-rheological properties of the oil disperse system are determined by the structure, size and composition of the complex structures resulting from the association of paraffins and tarry asphaltene components. Therefore, data about hydrocarbon composition, especially the structure of paraffins, tars and asphaltenes, required to choose recovery method in the extraction, field treatment, transportation and processing of heavy oils. In article parameters of the geometric and electronic structure of the tars and asphaltenes model molecules to determine reactivity indexes and, consequently, the possibility of a new oil dispersed system formation were calculated. Based on the density functional method B3LYP/6-311+G(d,p), quantum chemical calculations of the electronic structure and geometry of model tar molecules are given in the work. It was found that the number of benzene rings does not have a significant impact on the geometric and electronic structure of hydrocarbon fragments. The heteroatoms N, S and -OH functional group have a significant influence on the characteristics of model molecules. The nitrogen atom significantly increases the molecule dipole moment, compared to the sulfur and hydroxyl group, and the greatest change in geometric and electronic structure is observed in the presence of a sulfur atom. To choose recovery method in the heavy hydrocarbon crude treatment, the elemental composition is quite important, since it is heteroatoms in multi-core systems with condensed nuclei that affect the reactivity indices and provides generation of a free radical form and creation of a new oil dispersion system.

Compatibility of poly(dimethylsiloxane) microfluidic systems with high viscosity hydrocarbons

In this work, the compatibility of poly(dimethylsiloxane) (PDMS) with high viscosity petroleum liquids (bitumen) was evaluated to study the possibility of using PDMS microchannels in heavy oil and bitumen extraction research using solvent based methods such as Vapor Extraction. Three curing agent to base ratios (1:2, 1:10, and 1:20) were used to fabricate PDMS. Swelling ratio of these three samples in the vicinity of different organic solvents and diluted bitumen were evaluated by measuring the weight of sample every 15 min. It was found that 1:10 ratio PDMS was preferential ratio for minimizing absorption. We were particularly interested in the kinetic of swelling, deformation, and discoloration of PDMS. The hypothesis was that a PDMS microchip can still be used for experiments with heavy oil and bitumen if the experiment time is much shorter than the time it takes for PDMS discoloration, swelling, and deformation. The coating of PDMS slabs with trichloro (1 h 1 h 2 h 2 h-perfluorooctyl) silane was also tested and swelling ratios were again measured to evaluate the effect of surface coating. Swelling ratios were at the same order for uncoated PDMS which shows silane coating is not able to improve the solvent compatibility of PDMS. Moreover, solubility parameter was used to predict the swelling ratio of 1:10 PDMS sample in organic solvents. It predicts that hexane and toluene have the highest solubility that was in great agreement with experimental results. It seems that solubility parameter is a reliable factor to qualitatively predict the swelling ratio of PDMS. The effect of bitumen on transparency of PDMS was also studied using Ultraviolet–Visible spectrophotometer.